Arctic Ocean

Photo Courtesy of CIA World Factbook

The Arctic Ocean, located mostly in the north polar region, is the smallest of the world's five oceans, and the shallowest. Even though IHO recognizes it as an ocean, oceanographers may call it the Arctic Mediterranean Sea or simply the Arctic Sea, classifying it as one of the mediterranean seas of the Atlantic Ocean.

The Arctic Ocean occupies a roughly circular basin and covers an area of about 14,090,000 km² (5,440,000 mi²), slightly less than 1.5 times the size of the US. The coastline length is 45,389 km. Nearly landlocked, it is surrounded by the land masses of Eurasia, North America, Greenland, and a number of islands. It includes Baffin Bay, Barents Sea, Beaufort Sea, Chukchi Sea, East Siberian Sea, Greenland Sea, Hudson Bay, Hudson Strait, Kara Sea, Laptev Sea, White Sea and other tributary bodies of water. It is connected to the Pacific Ocean by the Bering Strait and to the Atlantic Ocean through the Greenland Sea.

An underwater ocean ridge, the Lomonosov Ridge, divides the Arctic Ocean into two basins: the Eurasian, or Nansen, Basin, which is between 4,000 and 4,500 m (13,000 and 15,000 ft) deep, and the North American, or Hyperborean, Basin, which is about 4,000 m deep. The topography of the ocean bottom is marked by fault-block ridges, plains of the abyssal zone, ocean deeps, and basins. The average depth of the Arctic Ocean is 1,038 m (3,407 ft), in part due to the large extent of continental shelf extant on the Eurasian side.

The greatest inflow of water comes from the Atlantic by way of the Norwegian Current, which then flows along the Eurasian coast. Water also enters from the Pacific via the Bering Strait. The East Greenland Current carries the major outflow. Temperature and salinity vary seasonally as the ice cover melts and freezes. Ice covers most of the ocean surface year-round, causing subfreezing temperatures much of the time. The Arctic is a major source of very cold air that inevitably moves toward the equator, meeting with warmer air in the middle latitudes and causing rain and snow. Little marine life exists where the ocean surface is covered with ice throughout the year. Marine life abounds in open areas, especially the more southerly waters. The ocean's major ports are the Russian cities of Murmansk and Arkhangelsk (Archangel). The Arctic Ocean is important as the shortest air route between the Pacific coast of North America and Europe overflies it.

Major chokepoint is the southern Chukchi Sea (northern access to the Pacific Ocean via the Bering Strait); strategic location between North America and Russia; shortest marine link between the extremes of eastern and western Russia; floating research stations operated by the US and Russia; maximum snow cover in March or April about 20 to 50 centimeters over the frozen ocean; snow cover lasts about 10 months.